Diarylazooxime complex of cobalt(III): synthesis, structure, ligand redox, DFT calculations and spectral characteristics

• Published in: Transition metal chemistry (Weinheim) 2022, Vol.47 (1), p.31-38
• Main Authors: Dinda, Soumitra, Sarkar, Koushik, Panda, Bikash Kumar, Pramanik, Kausikisankar, Ganguly, Sanjib
• Format: Article
• Language: English
• Subjects: Bonding strength; Catalysis; Chemical bonds; Chemistry; Chemistry and Materials Science; Chromophores; Crystallography; Electrochemical analysis; Hydrogen bonding; Hydrogen bonds; Inorganic Chemistry; Ligands; Organometallic Chemistry; Physical Chemistry; Pi-electrons
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1007/s11243-021-00485-1

By using a multifunctional diarylazooxime ligand L NOH 1 , incorporating electron deficient azo chromophore in conjunction with a pendant π -electron-rich naphthyl group, the trans dichloro bis complex of type [Co III (L NOH )(L NO− )Cl 2 ] 2 has been synthesized. The structure of the chelate has been determined by X-ray crystallography, thereby authenticating the presence of oxime-oximato hydrogen bond within the coordinated moiety. The stability of this complex is attributed to intra-molecular hydrogen bonding as well as due to strong Ph π –Ph π stacking interactions. The complex has been characterized by several spectroscopic techniques, and their electrochemical properties have been reported. These are further complemented by theoretical studies in the form of DFT and TDDFT. The visible excitation for the complex arises from mainly mixed singlet manifold 1 ILCT and 1 LLCT transitions. Graphical abstract